The semiconductor industry continues to improve the integration density of various electronic components (e.g., transistors, diodes, resistors, capacitors, etc.) by continual reductions in minimum feature size, which allow more components to be integrated into a given area. Semiconductor devices are used in a variety of electronic applications, such as personal computers, cell phones, digital cameras, and other electronic equipment, as examples.
Semiconductor devices are typically fabricated by forming an active device in a semiconductor layer and then sequentially depositing insulating or dielectric layers, conductive layers, and the like over the active devices to provide electrical insulation and conductive connections to the underlying active devices. The layers over the active device are patterned using masks for each layer. As each layer is formed, it is aligned with the layer below it to ensure that the mask used to form the layer features, openings or the like in a predefined location in the layer.
Corresponding numerals and symbols in the different figures generally refer to corresponding parts unless otherwise indicated. The figures are drawn to illustrate the relevant aspects of the embodiments and are not necessarily drawn to scale.